<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        html, body {
            margin: 0;
            height: 100%;
        }

        canvas {
            display: block;
        }

    </style>
</head>
<body onload="draw();">

</body>
<script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src="js/libs/dat.gui.min.js"></script>
<script>
    var renderer;
    function initRender() {
        renderer = new THREE.WebGLRenderer({antialias: true});
        renderer.setSize(window.innerWidth, window.innerHeight);
        //告诉渲染器需要阴影效果
        renderer.shadowMap.enabled = true;
        renderer.shadowMap.type = THREE.PCFSoftShadowMap; // 默认的是，没有设置的这个清晰 THREE.PCFShadowMap
        document.body.appendChild(renderer.domElement);
    }

    var camera;
    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
        camera.position.set(0, 40, 100);
        camera.lookAt(new THREE.Vector3(0, 0, 0));
    }

    var scene;
    function initScene() {
        scene = new THREE.Scene();
    }

    //初始化dat.GUI简化试验流程
    var gui;
    function initGui() {
        //声明一个保存需求修改的相关数据的对象
        gui = {
            directionalLight:"#ffffff", //点光源
            directionalLightIntensity:1, //灯光强度
            visible:true, //是否可见
            castShadow:true,
            exponent:30,
            target:"plane",
            debug:false,
            groundColor:"#00ff00",
            skyColor:"#0000ff",
            hemiLightIntensity:0.3
        };
        var datGui = new dat.GUI();
        //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）

        datGui.addColor(gui,"skyColor").onChange(function (e) {
            hemiLight.color = new THREE.Color(e);
        });
        datGui.addColor(gui,"groundColor").onChange(function (e) {
            hemiLight.groundColor = new THREE.Color(e);
        });
        datGui.add(gui,"hemiLightIntensity",0,1).onChange(function (e) {
            hemiLight.intensity = e;
        });
        datGui.addColor(gui,"directionalLight").onChange(function (e) {
            directionalLight.color = new THREE.Color(e);
        });
        datGui.add(gui,"directionalLightIntensity",0,5).onChange(function (e) {
            directionalLight.intensity = e;
        });
        datGui.add(gui,"visible").onChange(function (e) {
            directionalLight.visible = e;
        });
        datGui.add(gui,"castShadow").onChange(function (e) {
            directionalLight.castShadow = e;
        });
        datGui.add(gui,"debug").onChange(function (e) {
            if(e){
                var debug = new THREE.CameraHelper(directionalLight.shadow.camera);
                debug.name = "debug";
                scene.add(debug);
            }
            else{
                var debug = scene.getObjectByName("debug");
                scene.remove(debug);
            }
        });
    }

    var hemiLight,directionalLight;
    function initLight() {
        hemiLight = new THREE.HemisphereLight(0x0000ff,0x00ff00,0.3);
        hemiLight.position.set(0,500,0);
        scene.add(hemiLight);

        directionalLight = new THREE.DirectionalLight("#ffffff");
        directionalLight.position.set(-40, 60, -10);

        directionalLight.shadow.camera.near = 20; //产生阴影的最近距离
        directionalLight.shadow.camera.far = 200; //产生阴影的最远距离
        directionalLight.shadow.camera.left = -50; //产生阴影距离位置的最左边位置
        directionalLight.shadow.camera.right = 50; //最右边
        directionalLight.shadow.camera.top = 50; //最上边
        directionalLight.shadow.camera.bottom = -50; //最下面

        //这两个值决定使用多少像素生成阴影 默认512
        directionalLight.shadow.mapSize.height = 1024;
        directionalLight.shadow.mapSize.width = 1024;

        console.log(directionalLight);

        //告诉平行光需要开启阴影投射
        directionalLight.castShadow = true;

        scene.add(directionalLight);
    }

    var cube,plane;
    function initModel() {

        //辅助工具
        var helper = new THREE.AxisHelper(10);
        scene.add(helper);

        //球体
        var sphereGeometry = new THREE.SphereGeometry(10,30,30);
        var sphereMaterial = new THREE.MeshStandardMaterial({color:0xeeeeee});
        var sphere = new THREE.Mesh(sphereGeometry,sphereMaterial);
        sphere.position.set(-20,20,0);

        sphere.castShadow = true;

        scene.add(sphere);

        //立方体
        var cubeGeometry = new THREE.CubeGeometry(10,10,10);

        var cubeMaterial = new THREE.MeshLambertMaterial({color: 0x00ffff});

        cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
        cube.position.x = 30;
        cube.position.y = 5;
        cube.position.z = -5;

        //告诉立方体需要投射阴影
        cube.castShadow = true;

        scene.add(cube);

        //底部平面
        var planeGeometry = new THREE.PlaneGeometry(5000, 5000, 20, 20);
        var planeMaterial = new THREE.MeshLambertMaterial({color: 0xaaaaaa});

        plane = new THREE.Mesh(planeGeometry, planeMaterial);
        plane.rotation.x = -0.5 * Math.PI;
        plane.position.y = -0;

        //告诉底部平面需要接收阴影
        plane.receiveShadow = true;

        scene.add(plane);

    }

    //初始化性能插件
    var stats;
    function initStats() {
        stats = new Stats();
        document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;
    function initControls() {

        controls = new THREE.OrbitControls(camera, renderer.domElement);

        // 如果使用animate方法时，将此函数删除
        //controls.addEventListener( 'change', render );
        // 使动画循环使用时阻尼或自转 意思是否有惯性
        controls.enableDamping = true;
        //动态阻尼系数 就是鼠标拖拽旋转灵敏度
        //controls.dampingFactor = 0.25;
        //是否可以缩放
        controls.enableZoom = true;
        //是否自动旋转
        controls.autoRotate = false;
        //设置相机距离原点的最远距离
        controls.minDistance = 50;
        //设置相机距离原点的最远距离
        controls.maxDistance = 200;
        //是否开启右键拖拽
        controls.enablePan = true;
    }

    function render() {
        renderer.render(scene, camera);
    }

    //窗口变动触发的函数
    function onWindowResize() {

        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        render();
        renderer.setSize(window.innerWidth, window.innerHeight);

    }

    function animate() {
        //更新控制器
        render();

        //更新性能插件
        stats.update();

        controls.update();

        requestAnimationFrame(animate);
    }

    function draw() {
        initGui();
        initRender();
        initScene();
        initCamera();
        initLight();
        initModel();
        initControls();
        initStats();

        animate();
        window.onresize = onWindowResize;
    }
</script>
</html>